1. Field of the Invention
The present invention relates to a computer system, and more particularly, to a scroll method of a computer system.
2. Description of the Prior Art
Window-based operating systems are commonly used in computer systems for editing and browsing documents. In a window-based operating system, a document is displayed in an image frame which is contained in a window, and the window is displayed in a monitor of a computer system. However, the image frame often cannot display the document in full because the display area of the image frame has a limited size. In order to view a hidden portion of the document below the image frame, a user has to move the cursor to a down arrow of a vertical scroll bar, and click on one of the buttons of a mouse. Once the button is clicked, the document will move upward line-by-line. Vice versa, if the button is clicked when the cursor is positioned on an up arrow of the vertical scroll bar, the document will move downward line-by-line.
In computer programming, the command for scrolling is SendMessage(hWnd, WH_VSCROLL, SB_LINEUP, NULL). The parameter which causes the line movement is SB_LINEUP. The line movement is very disturbing for the user, thus research has been focusing on more comforting means to scroll the document.